Abstract: Effects of different formulations, plasticizers and lipids on the water resistant properties of potato starch/sodium alginate composite cross-linked edible films were analyzed.The results showed that, compared with the films with high sodium alginate component, films with high potato starch had lower water vapor permeability coefficient ( Pv) and higher water solubility.With the increase of plasticizers ( glycerol, sorbitol and glycerol sorbitol mixture) , both Pv and water solubility of the films were increased. The films with ratio of 1 ∶ 1 mixed glycerol and sorbitol as the plasticizer had the lower Pv and water solubility.Add lipids to the films would reduce Pv and the films with olive oils had lower PV than these with stearic acid.